Electric power supply system having active power control device

Abstract

As a component of an aerial vehicle, a power management system having an active power control device is provided. The system includes a solar cell converting solar energy into electric energy; a fuel cell provided in the aerial vehicle and converting fuel energy into electric energy by electrochemical reaction; a battery compensating for a lack of electric power supplied from the solar cell and the fuel cell to the aerial vehicle and storing surplus electric power; and an active power control device connecting with all the solar cell, the fuel cell and the battery and combining and distributing electric power generated in the solar cell, the fuel cell and the battery to loads. The system efficiently distributes the power from the respective power sources through the controllable output of the fuel cell in accordance with power required by the aerial vehicle and the solar cell's performance depending on weather.

The invention claimed is: 
     
       1. A power management system with an active power control device for supplying power to an aerial vehicle as a component of the aerial vehicle, the power management system comprising:
 a solar cell converting solar energy into electric energy; 
 a fuel cell provided in the aerial vehicle and converting fuel energy into electric energy by electrochemical reaction; 
 a battery compensating for a lack of electric power supplied from solar cell and the fuel cell to the aerial vehicle and storing surplus electric power; and 
 an active power control device connecting with all the solar cell, the fuel cell and the battery and combining and distributing electric power generated in the solar cell, the fuel cell and the battery to loads. 
 
     
     
       2. The power management system with the active power control device according to  claim 1 , wherein the active power control device comprises:
 a maximum power point tracker (MPPT) for the solar cell, which converts output of the solar cell into power and supplies the power to an output terminal; 
 a converter for the fuel cell which controls output of the fuel cell; 
 a charging circuit which maintains a state of charge (SOC) of the battery at an optimum level by charging the battery with surplus power of the solar cell and working the fuel cell; and 
 a processor board which controls output of the MPPT for the solar cell and the converter for the fuel cell. 
 
     
     
       3. The power management system with the active power control device according to  claim 2 , wherein the active power control device further comprises a separate dedicated (small) auxiliary battery for backup in preparation for an interruption or lack of power sources. 
     
     
       4. The power management system with the active power control device according to  claim 2 , wherein the MPPT for the solar cell comprises:
 an MPPT module provided for normal output of the solar cell; 
 a bypass module arranged in parallel with the MPPT module and provided for abnormal output when the MPPT module breaks down; 
 an MPPT module monitoring timer connecting with the MPPT module and monitoring a toggle signal applying time of the MPPT module; 
 a PM mode monitoring timer connecting with the MPPT module and monitoring whether a PM mode operation signal of the MPPT module is output; 
 an OR gate applying OR logic to signals output from the MPPT module monitoring timer and the PM mode monitoring timer; and 
 a bypass switch connected to an output terminal of the OR gate and tuned on or off. 
 
     
     
       5. The power management system with the active power control device according to  claim 4 , wherein in a case where power is supplied from the solar cell to the MPPT for the solar cell,
 if the MPPT module outputs a heartbeat signal as a toggle signal within a few seconds, the MPPT module monitoring timer for monitoring the MPPT module outputs a low signal, and 
 if the PM mode monitoring timer does not sense the PM mode operation signal of the MPPT module and outputs a low signal, the OR gate turns off the bypass switch connected to the output terminal thereof so that power can be output through the MPPT module. 
 
     
     
       6. The power management system with the active power control device according to  claim 4 , wherein in a case where power is supplied from the solar cell to the MPPT for the solar cell,
 if a heartbeat signal is not toggled in the MPPT module for a few seconds, the MPPT module monitoring timer for monitoring the MPPT module outputs a high signal, and 
 if the PM mode monitoring timer does not sense the PM mode operation signal of the MPPT module and outputs a low signal, the OR gate turns on the bypass switch connected to the output terminal thereof so that power can be bypassed through the bypass module. 
 
     
     
       7. The power management system with the active power control device according to  claim 2 , wherein the converter for the fuel cell comprises
 a DC-DC module provided for normal output of the fuel cell; 
 a bypass module arranged in parallel with the DC-DC module and provided for abnormal output when the DC-DC module breaks down; and 
 a processor board monitoring timer connecting with the processor board; 
 an OR gate applying OR logic to signals output from the processor board monitoring timer and a PGOOD terminal of the DC-DC module; and 
 a bypass switch connected to an output terminal of the OR gate and turned on or off. 
 
     
     
       8. The power management system with the active power control device according to  claim 7 , wherein in a case where power is supplied from the fuel cell to the processor board and the DC-DC module,
 if a main central processing unit (CPU) of the processor board outputs a toggled heartbeat signal within a few seconds, the processor board monitoring timer connected to the processor board outputs a low signal, and 
 if the PGOOD terminal of the DC-DC module outputs a high signal and the high signal is inversed at an output terminal and output as a low signal, the OR gate receives the low signals and turns off the bypass switch connected to the output terminal thereof so that power can be output through the DC-DC module. 
 
     
     
       9. The power management system with the active power control device according to  claim 7 , wherein in a case where power is supplied from the fuel cell to the DC-DC module and the processor board is not booted up,
 if a toggled heartbeat signal is not output from the main CPU of the processor board for a few seconds, the processor board monitoring timer for monitoring the processor board outputs a high signal, and 
 if the PGOOD terminal of the DC-DC module outputs a low signal and the low signal is inversed at an output terminal and output as a high signal, the OR gate receives the high signals and turns on the bypass switch connected to the output terminal thereof so that power can be bypassed through the bypass module. 
 
     
     
       10. The power management system with the active power control device according to  claim 7 , wherein
 if power is supplied from the fuel cell to the processor board and the DC-DC module, but the DC-DC module does not normally work, the processor board monitoring timer outputs a low signal since a toggle signal is toggled in the processor board for a few seconds, and 
 if the PGOOD terminal of the DC-DC module outputs a low signal, and the low signal is inversed at an output terminal and output as a high signal, the OR gate receives the low signal and the high signal and turns on the bypass switch connected to the output terminal thereof so that power can be bypassed through the bypass module.